Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation work + error analysis

Independently replace leaky piping in the toilet room is not easy, but possible. The main problems here arise because of the constraint in the bathroom. Many owners do not want to get rid of the old toilet, and replacing pipes in the toilet with already installed plumbing is still a pleasure.

On the one hand, there is not enough space for work, and on the other hand, additional efforts have to be made in order not to accidentally damage the sanitary ware.

Diagnostics of pipe condition

Before you go to the store to buy new pipes, you need to think once again whether you need to do such repairs at all and in what volumes it should be made. If you plan to work in the toilet, which is located in a private house, then this is one situation. Here the master master will not interfere.But when working in an apartment high-rise buildings will be a lot of problems.

When replacing risers in an apartment, it is necessary to coordinate your actions with your neighbors in advance. And this is not only a tribute. There are several points here that, having forgotten about them, will not face long serious problems.

Old pipes in the toilet
Changing risers in an apartment toilet should be trusted only to plumbers of a company’s apartment building, they are better informed to outsiders about the condition of pipes in this particular building

The first is that water supply pipes can be closed in the basement of the porch for several hours without asking anyone. During the day, plumbers do this quite often in apartment buildings. Neighbors in the daytime at work, most of them do not even know about the break in the water supply. However, the sewer riser should not be dismantled without warning.

Even if you turn off the cold water in the house, it still remains in the cisterns. And with the disassembled sewer riser all fecal masses that will be washed away on the floors above, will certainly be in your toilet. It is better to communicate with the neighbors in advance and warn them about the work being done so that they do not use the plumbing for a couple of hours.

The second point is the pipes in the area in the interfloor overlap. These risers are considered the most vulnerable and most problematic. It is here that the metal rusts the fastest. When completely replacing the pipelines, they must be taken from above and below through reinforced concrete. That is, welding and otherwise connecting new pipes with old ones will probably have to be performed in neighboring apartments on the floor above and below.

After learning about the repair, the neighbors may well decide to change the risers at the same time as you. This will save a little on the material and the call of locksmiths, who will come to block the water in the basement during the repair.

Breaking through the floor slab
If the sewers and water pipelines are changed in several apartments at once, then it will be cheaper for each owner than to call plumbers alone

The third point is the condition of the pipes. Often, water and sewer risers just look useless from the outside. But when cutting the old iron pipeline, there are cases when it is covered with rust only outside. If it does not flow, it is often not worth replacing it. Inside, everything can be perfect, the walls are still able to last a couple of decades.

This happens when there is poor ventilation in the toilet.Condensate accumulates on metallic water conduits outside, leading to rust. However, corrosion only affects the outer surface of the pipeline. Then it is only necessary to clean the sandpaper and paint a good paint.

Changing pipes in such a situation is only wasting money. The replacement of the cast-iron sewer riser should be carried out on plastic at all when it is destroyed externally. Old cast iron is more durable and less “noisy” than modern plastic.

What is the layout

If the toilet in the apartment or cottage is not combined with the bathroom, then special problems with the preparation of the layout of pipelines are unlikely to arise. As a rule, there is only one toilet in it and there are two risers, from which it is necessary to bring a couple of pipes to this single plumbing fixture.

However, next to the wall there is usually a kitchen and a bathroom, where you also need to lay pipelines. Here, with their wiring, basically, there are difficulties when replacing pipes.

Connecting the toilet
Plumbing is connected to the water sockets by a rigid or flexible (through the drain hoses) method, to the sewer toilet bowls are connected only in the first embodiment or corrugated

There are two technologies for laying pipes in the bathroom:

  1. Outdoor
  2. Hidden.

The first method is simpler to perform, and the second is more aesthetically good. With the hidden laying of pipelines have to stitched the walls, and this is dirt and extra preparation time. The best option is to lay the pipes in the toilet according to the external scheme, and then cover them with a decorative box. Especially since the risers should be closed with decor anyway. If you leave them open, the interior of the bathroom will look ugly.

With a hidden gasket, any leakage then immediately turns into a headache. We must start over again all over again. We'll have to remove the lining, break the walls and change the pipes again.

False wall with hatch
A good option with exterior styling with decorative false walls and ducts. The latter have inspection hatches and are easily removed if necessary, if you need to get to the leaking pipelines.

Sewer pipe is laid with a slope to the riser to ensure the drift. In the places of installation of sanitary devices, tees are inserted into it with the location of the sockets to meet the movement of drains.The slope, according to building codes, is selected based on the diameter of the pipeline. The smaller the section, the more the latter must be tilted.

For a house sewer pipe with a diameter of up to 50 mm, the slope is 3 degrees (3 cm in height per linear meter). For products with a cross section of 50–110 mm, it is recommended at 2 degrees, and for analogs at 110–160 mm - at the level of 0.8 degrees.

Plumbing to the water supply is connected:

  • according to the sequential scheme;
  • through the collector at the riser.

The collector option is more expensive, but the pressure on each water outlet with such wiring is always the same. The pressure of water in this case in the faucets and the soul does not jump when you turn on the washing machine or filling the toilet bowl.

Collector layout
When using the collector scheme of water supply from the riser to the sanitary devices, pipes will have to be installed a lot, and all this household is usually located just in the toilet

Water sockets are attached directly to the walls or on the traverse (metal plates with holes for fasteners). At the same time drainage for the toilet in the toilet is the easiest to do with a hose. On the conductive by-pass water supply system with cold-water, a tee insert is simply made with a terminal having an external or internal thread.Ideally, pipes should be installed everywhere in parallel, without intersection with each other.

Stopcocks in the toilet
Immediately from the riser and at the end of each tap of a water supply a stopcock is installed. This is necessary so that, if necessary, it was possible to disconnect only one sanitary device for its replacement or repair.

From the water supply tower, first a ball valve is installed, then a coarse filter, and only then a counter. The simplest and cheapest filter is a mechanical one without backwashing (with a small straight or oblique process, with a sump mesh inside). On it from time to time you have to unscrew the cap with a wrench to wash the accumulating sand and rust of the stainless steel mesh.

Filter with autowash has large dimensions. It must be connected to the sewage system, and also install a bypass bypass parallel to it. If there is little space on the wall of the toilet, then it is better to refuse this option. All this in the complex is called the “input node”. After it is already a pipe for connecting plumbing or collector.

Selection of building materials

The ideal building material does not exist. In each case, selected its own version, the most suitable for specific conditions.When replacing pipelines in the toilet, you must purchase the pipes themselves, fittings and valves for them. It does not hurt to design the box in advance and purchase finishing materials for it. Then all the work will take a maximum of one day.

How to choose pipes for sewage

With sewer pipes the easiest. If the existing cast-iron riser does not have cracks and holes, then you should not change it. Otherwise, you should choose plastic tees and taps. These pipe products are lightweight and easy to install. The connection between them is made in the socket, having a rubber cuff. The most difficult thing is to cut such pipes with a hacksaw into a segment of the required length, without forgetting to process the end face from burrs.

Cast iron pipeline
Disconnect the sewage cast-iron parts should be carefully, this metal is very fragile - to beat on it with a hammer or press on the fracture with a large lever is prohibited

For installation in the toilet sold plastic sewer pipes from:

  1. PVC
  2. Polypropylene.
  3. Polyethylene

The cheapest option is polyvinyl chloride. But polyethylene and polypropylene are more resistant to household chemicals and temperature changes that occur when hot water is drained into the sewer system.However, in general, any of these materials will be suitable for a toilet in an apartment and a private house.

Previously, cast iron pipes were connected with cement or sulfur. In the first case, the joint will have to be slowly broken up with a screwdriver, and in the second - with a burner. Removing one element from another should be carefully looted back and forth, otherwise the socket will crack and you will have to change much more pipes. For the connection of plastic and cast iron, an appropriately sized rubber cuff will be sufficient.

Types of pipes for hot and cold water systems

Water pipes for replacement in the toilet, you can take:

  • steel stainless steel;
  • copper;
  • polypropylene;
  • polyethylene;
  • polyvinyl chloride;
  • metal plastic.

Steel and copper pipes will have to be connected by welding (soldering), so for self-assembly they are rarely taken. Stainless steel is often used by fitters to replace old iron risers. This option is the most reliable. The joints of new and old sections of such a pipe with high-quality welding almost never leak.

Pipe distribution in the toilet
When self-replacing toilet pipelines for cold and hot water supply, it is recommended to choose plastic pipes,they are cheap and easy to connect in various ways

For cold plumbing in the apartment plastic pipes should be purchased with the marking PN10. This thin-walled version is designed for a working pressure of 1 MPa and a water temperature of up to +200S. For cold-water this will be enough. For DHW require analogue with PN20 and above. It has a thicker wall and higher operating parameters for temperature and pressure.

Pipes PP (PP) are connected by diffusion welding using fittings and butt. The connection is one-piece. Compression or press fittings are used for the installation of metal-plastic. This is the easiest material for self-assembly of the pipeline. Plus, if necessary, the water supply can be easily disassembled to replace or insert new plumbing.

PVC mounted on glue butt or fitting connection. PE (HDPE) at home are connected by electrofusion welding or compression joints.

Metal pipes are good opportunity to fold in the corners of the room, they are the most plastic of all analogs of plastic. Fittings for them, however, are expensive. Polypropylene plumbing is cheaper to connect, but because of the large thermal expansion, they often sag on the DHW. PVC is cheap, but for the supply of hot water will have to pick up another option.

How not to make a mistake when dismantling / installing pipes

When planning the replacement of pipes in the toilet, it should be remembered that it will not be limited to one room with a toilet. The sewage pipeline will have to be completely replaced. Separately, to change the plumbing only in the toilet, without affecting the areas in the bathroom and kitchen, is also hardly a reasonable undertaking. If you update the pipe, then immediately completely from the riser to all without exception of sanitary devices.

Sewage scheme in the apartment
In most cases, the sewage pipe in the toilet is only a small segment of the entire internal drainage system.

Iron casting tees should be disconnected and new plastic bends should be inserted into them solely by rotating movements. Cast iron is too fragile to press hard on it and even more so to beat it with a heavy tool. But if such a stand in the plans to completely remove, then break it into separate pieces would be easy.

All existing flexible liner in the sheath, going to the toilet or sink, you should immediately throw out when dismantling. Their service life usually does not exceed five years. It is better to change them without thinking about new ones. The situation is similar with all the old valves.If she has served more than 3-4 years, then replacement is required. Risk is not worth it.

Sewer joints
The joints of the drainage pipes and sewage pipes, as well as the points of connection of plumbing to it, should be sealed with cuffs or silicone. Otherwise, the toilet itself and the adjoining rooms will fill the amber sewer

Shaped parts can not be cut or in any way changed. Their trumpet should look towards the movement of wastewater.

Without exception, water supply pipes must end with stopcocks. Ideally, before each device plumbing needs its own valves with ball locks. This in the future will greatly simplify life with the connection and replacement of equipment in the bathroom and kitchen.

Before closing the pipes with a decor, the system should be crimped. It is necessary to supply water through all pipelines and include all plumbing fixtures. And then you need to check the joints for drips and leaks. Only in the case of their complete absence, you can begin to finish the toilet.

Conclusions and useful video on the topic

To make it easier for you to understand all the nuances of pipe replacement, we made a selection of video materials explaining all the subtleties and tricks of the process.

How should not change pipes and plumbing:

All about the proper installation of domestic sewage:

The tricks of replacing a combined bathroom of metal pipes with plastic:

Replacing the old toilet pipe sewer and water is easy. There are some subtleties in this work, but if you like, you can do everything yourself. Only before you dismantle the existing risers, it is worth a close look at them. Old pipelines are often able to last for many years. This is especially true of the sewer system.

Related news

Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors image, picture, imagery


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 6


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 7


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 24


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 81


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 59


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 4


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 96


Replacing the pipes in the toilet from A to Z: design, selection of building materials, installation, analysis of errors 67